ANNUAL REPORT - MTA SzFKI

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M. LASER PHYSICS K. Rózsa, G. Bánó, L. Csillag, A. Derzsi # , Z. Donkó, P. Hartmann, P. Horváth # , Z.Gy. Horváth, K. Kutasi, P. Mezei Computational plasma studies. — We have investigated the electron kinetics in a hollow cathode discharge by a coupled fluid - Monte Carlo model, and through the solution of the Boltzmann equation. Simulations were carried out to uncover the role and effects caused by fast neutral species in low-pressure gas discharges. Such species originate from elastic collisions between fast ions and thermal buffer gas atoms and were found to cause significant excitation of the gas near the cathode and to induce enhanced emission of electrons from the cathode surface. Langmuir probe measurements were carried out in conjunction with numerical simulations to determine basic characteristics of helium glow discharges. The probe measurements have confirmed the presence of a nearly thermal electron population in the negative glow region of the discharge. In the field of strongly coupled plasma physics we have performed molecular dynamics (MD) simulations and investigated thermodynamic and collective properties of (i) classical bipolar bilayer systems, (ii) two-dimensional many-particle system characterized by Yukawa type interaction potential, including studies of the solid-liquid phase transition, as well as the shear viscosity and shear thinning effect in this latter system in the liquid phase. Hollow cathode lasers. — Near 200 nm deep ultraviolet hollow-cathode metal ion lasers can be used as light sources for UV Raman and laser-induced fluorescence spectroscopy. These lasers are usually excited by charge transfer reactions between noble gas ions and metal atoms. High density of noble gas ions is created in hollow-cathode discharges while the necessary metal atom density can be produced either by thermal evaporation or utilizing the cathode sputtering effect of the discharge. Our recent investigation is focused on the development of a sputtered 224 nm segmented hollow-cathode silver ion laser. A novel discharge arrangement has been developed in order to prolong the lifetime of the laser tube. 220 mW peak power has been achieved using our previous model. Recently we are working towards a practical sealed-off laser version that will be tested for Raman spectroscopic measurements in bio-medical applications. Electrolyte cathode atmospheric pressure glow discharge (ELCAD). — In a normal and an abnormal ELCAD plasmas the density of electrons (n e ) and positive ions (n + ) were estimated from the earlier measured values of the cathodic current density (j c ), the cathode fall (U cf ), the electric field (E c ), the length of cathode dark space (CDS) (d), the kinetic energy (E ion ), the last free path of positive ions hitting the cathode (l) and the rate of secondary electron emission (γ). In a normal ELCAD, the density of positive ions forming the space charge: n + sp ≈ 5.7×10 12 cm −3 , the density of positive ions hitting the cathode: n + ≈ 1.1×10 12 cm −3 , the electron density at the cathode: n e,c ≈ 3.7×10 11 cm −3 , the multiplication of electron in cathode dark space M ≈ 15.3 were obtained, thus the electron density at the end of cathode dark space: n e ≈ 5.7×10 12 cm −3 . This electron density agrees well with n e ≈7x10 12 cm -3 and n e ≈10 12 cm -3 which were obtained in the center of an ELCAD plasma by other experiments. For abnormal (capillary cell) ELCAD due to its higher j c , E ion, U cf, l, and shorter d values compared with those of a normal one , n + ≈ 4.3x10 12 cm -3 , n + sp≈ 2.1x10 13 cm -3 , M≈1.64, and n e ≈ 2.1x10 13 cm -3 were estimated. These data indicate that the higher charge density # Ph.D. student 60
values in an abnormal ELCAD are mainly produced through the enhanced rate of secondary electron emission and not through an increased ionization in a shorter CDS. These values are lower by 1-1.5 order of magnitude than that obtained from the measured Stark-broadening of the emitted H β =486.1 nm line. The possible reason of this significant difference may be that, the Stark broadening method using H β =486.1 nm emission line can be used with acceptable reliability for determination of n e only if n e is larger than 10 15 –10 16 cm -3 . Multispectral imaging reflectometer. — The development of a new type of optical reflectometers was successfully finished, in cooperation with the Research Institute for Technical Physics and Materials Sciences, supported by a GVOP grant. The „preindustrial” application of the prototype starts in Germany at the end of this year. E-Mail: Károly Rózsa karcsi@sunserv.kfki.hu Gergely Bánó bano@sunserv.kfki.hu László Csillag csillag@szfki.hu Aranka Derzsi derzsi@sunserv.kfki.hu Zoltán Donkó donko@sunserv.kfki.hu Péter Hartmann hartmann@sunserv.kfki.hu Péter Horváth phorvath@sunserv.kfki.hu Zoltán Gy. Horváth horvath@szfki.hu Kinga Kutasi kutasi@sunserv.kfki.hu Pál Mezei mezeipal@szfki.hu Grants and international cooperations OTKA T-48389 Modern plasma simulation techniques (Z. Donkó, 2005–2008) OTKA IN-69892 Simulation of strongly-coupled many-particle systems (Z. Donkó, 2006–2008) MRTN-CT-2006-035459 GLADNET: Analytical Glow Discharge Network (Z. Donkó, 2007-2011) OTKA PD-049991 Post-doc position (P. Hartmann, 2005–2008) <strong>MTA</strong>-OTKA-NSF 90/46140 Strongly coupled Coulomb systems (Z. Donkó, 2005-2007) TÉT Port 14/2005 Electron kinetics in gas mixtures (Z. Donkó, 2006-2008) <strong>MTA</strong>-CSIC #8 Use of kinetic methods to study the electron energy distribution function and plasma chemistry of SPRITE discharges produced in the mesosphere and lower ionosphere: Impact on the ozone chemistry. (Z. Donkó, 2007-2008) OTKA T-042493 The role of the ions of the basic electrolyte solution in the electrolyte OTKA K-68390 cathode atmospheric glow discharge (P.Mezei, 2003-2007) Investigations of the atomization processes in the electrolyte cathode atmospheric glow discharge (P.Mezei, 2007-2011) GVOP-3.1.1.-2004-05-0435/3.0 Multispectral imaging reflectometer (M.Fried and Z.Gy. Horváth, 2005-2007) 61
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ANNUAL REPORT 2007 RESEARCH INSTITU
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Dear Reader, It is my pleasure to h
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Key figures Permanent staff of the
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A. STRONGLY CORRELATED SYSTEMS J. S
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presented detailed study should hel
Page 12 and 13: B. COMPLEX SYSTEMS F. Iglói, R. Ju
Page 14 and 15: B.3. B.4. B.5. B.6. B.7. B.8. B.9.
Page 16 and 17: the α2 reconstruction increases on
Page 18 and 19: C.2. C.3. Kádas K, Vitos L, Johans
Page 20 and 21: C.27. Ropo * M, Kokko * K, Punkkine
Page 22 and 23: I 25 4 3 Fig. 2. Average intensity
Page 24 and 25: See also H.6. and nanostructured Pd
Page 26 and 27: Ab initio structure solution. — I
Page 28 and 29: ESA PECS 98021 Phase field modeling
Page 30 and 31: Conference proceedings E.17. Oszlá
Page 32 and 33: Fig. 1. ns-EC to s-EC transition in
Page 34 and 35: Publications Articles F.1. F.2. Bö
Page 36 and 37: G. ELECTRON CRYSTALS G. Kriza, P. M
Page 38 and 39: H. METAL PHYSICS K. Tompa, I. Bakon
Page 40 and 41: thickness can be elucidated by deco
Page 42 and 43: I. METALLURGY AND MAGNETISM L.K. Va
Page 44 and 45: temperature profile increases the s
Page 46 and 47: I.13 Kane * SN, Khinchi * SS, Gercs
Page 48 and 49: SANS. The measured 3 control rods w
Page 50 and 51: J.3. J.4. J.5. J.6. J.7. Avdeev * M
Page 52 and 53: Macromolecular Compounds (Visokomol
Page 54 and 55: defined coordination sphere was fou
Page 56 and 57: László Temleitner temla@szfki.hu
Page 58 and 59: Book chapter K.22. Temleitner L, Pu
Page 60 and 61: Fig. 1 Characteristics of surface p
Page 64 and 65: Publications Articles M.1. Sigenege
Page 66 and 67: O. LASER APPLICATION A. Czitrovszky
Page 68 and 69: Raman spectroscopy is widely used f
Page 70 and 71: Bilateral Austro-Hungarian Cooperat
Page 72 and 73: P. FEMTOSECOND LASERS R. Szipőcs,
Page 74 and 75: Grants and international cooperatio
Page 76 and 77: E-Mail: Kárpát Ferencz optilab@t-
Page 78 and 79: y optical microscopy. While in Y 2
Page 80 and 81: Publications: Articles R.1. Földv
Page 82 and 83: S. CHARACTERIZATION AND POINT DEFEC
Page 84 and 85: groups of the Li 2 B 4 O 7 lattice.
Page 86 and 87: S.10. Lengyel K, Kovács L, Péter
Page 88 and 89: entanglement one has to find method
Page 90 and 91: T.7. T.8. T.9. Asbóth JK, Domokos
Page 92 and 93: EDUCATION Graduate and postgraduate
Page 94 and 95: Laboratory practice and seminars
Page 96 and 97: G. Dravecz (ELTE and Université de
Page 98 and 99: ⎯ K. Kamarás: Editorial Board Me
Page 100 and 101: CONFERENCES ⎯ Electrochemistry se
Page 102: TABLE of CONTENTS PREFACE 1 KEY FIG
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